Rare earth metal compounds for use in high critical temperature thin film super-conductors, ferroelectrics, pyroelectrics, piezoelectrics, and hybrids

ABSTRACT

Rare earth metal containing compounds of the general formula Sr 2 RESbO 6 , wherein RE is a rare earth metal, have been prepared with high critical temperature thin film superconductor strucutures, and can be used in other ferroelectrics, pyroelectrics, piezoelectrics, and hybrid device structures.

CONTINUATION-IN-PART

This application is a continuation in part of U.S. Patent and TrademarkOffice application Ser. No. 09/337,724, entitled, “Rare Earth MetalContaining Compounds and High Critical Temperature Thin FilmSuperconductors, Ferroelectrics, Pyrolelectrics, Piezoelectrics andHybrids Including the Rare Earth Metal Containing Compounds,” filed onJun. 21, 1999, now abandoned, which was a continuation in part of U.S.Patent and Trademark Office application Ser. No. 08/717,822 with thesame title, filed on Sep. 24, 1996, now abandoned. That application(Ser. No. 08/717,822) was a continuation in part of U.S. Patent andTrademark Office application Ser. No. 08/333,669 with the same title,filed on Nov. 3, 1994, now abandoned. This continuation in part is beingfiled under 37 CFR. § 1.53.

RELATED APPLICATION

Assigned U.S. Patent Office application Ser. No. 08/502,739, entitled“Compounds in the Series A₂MeSbO₆ for Use as Substrates,Barrier-Dielectric Layers and Passivating Layers in High CriticalTemperature Superconducting Devices,” which has been assigned to thesame assignee issued as U.S. Pat. No. 5,814,584 on Apr. 29, 1998 and isrelated to this application.

GOVERNMENT INTEREST

The invention described herein may be manufactured, used, and licensedby or for the Government for governmental purposes without the paymentto us of any royalties thereon.

FIELD OF INVENTION

The invention relates in general to new and useful devices composed ofrare earth metal containing compounds, and in particular to new usesdielectric substrates and buffer layers composed of compounds of thegeneral formula Sr₂RESbO₆ where RE is a rare earth metal.

BACKGROUND OF THE INVENTION

Heretofore, the best substrate or barrier dielectric in thin filmsuperconductor technology has been LaAlO₃. However, there have beenproblems with the use of LaAlO₃. For one, its dielectric constant isanisotropic and too high. This automatically prevents one from makingcertain types of devices. It also undergoes a phase transition leadingto twinning and stress. The present invention provides a solution tomany of the shortcomings and problems associated with the use of LaAlO₃.

SUMMARY OF THE INVENTION

The general object of this invention is to provide materials that can beused as a substrate or barrier dielectric in thin film superconductortechnology that can overcome the problems, shortcomings and limitationsof LaAlO₃. A more particular object of the invention is to provide asubstrate or barrier dielectric with a low dielectric constant, a lowdielectric loss, and a material that does not undergo a phase transitionthat leads to twinning and stress. It is a further object of the presentinvention to provide compounds and structures producing tetragonalphases that are extremely useful as dielectric substrates and bufferlayers for YBCO and other thin film superconductor devices.

It has now been found that the aforementioned objects can be attainedusing a compound of the general formula Sr₂RESbO₆ where RE is a rareearth metal as the substrate or barrier dielectric in thin filmsuperconductor technology. In the above formula, RE can be Lu, Yb, Tm,Er, Ho, Dy, Th, La, Pr, Y Sm, Nd, Eu or Gd. These compounds can be usedas barrier or buffer layers and substrates in thin film high criticaltemperature superconducting structures, as well as antennas and otherdevices such as ferroelectrics, pyroelectrics, piezoelectrics andhybrids.

DESCRIPTION OF THE INVENTION

Indexed powder diffractometer data taken using CuKa radiation, revealsthese compounds to be ordered perovskites. With the exceptions ofSr₂LuSbO₆ and Sr₂LaSbO₆ that are cubic, all of the other compounds arefound to be pseudo-cubic, tetragonal. Single and multilayer thin filmsare prepared by KrF pulsed laser ablation. By thin films is meant filmthicknesses ranging from about 100 Å to about 10 μm. All Sr₂RESbO₆ filmsexhibit a primary (h00) and a secondary (2n, 2n,0) orientation.Dielectric constants and losses are measured in bulk samples by a cavityperturbation technique at X band and on films by an impedance bridge at1 MHz. The term “low dielectric loss,” as used throughout thisdisclosure, is defined as any dielectric loss lower than 1×10⁻². Theterm “low dielectric constant,” as used throughout this disclosure, isdefined as any dielectric constant lower than 20, and, in this inventionranges from 5.1-16.3 in the bulk form and from 4.1-16.3 in the thin filmform, within an experimental error of +/−5%. Results are given in theTABLE I, below and while dielectric constants for thin films aregenerally similar to the bulk values, factors such as densitydifferences between the bulk and thin film samples result in differencesin dielectric constant in some cases.

The following compounds in the series Sr₂RESbO₆ have been synthesizedfor use as dielectric substrates or barrier layers or passivation layersin thin film high critical temperature superconductor devices:

TABLE 1 Lattice Parameter Dielectric Dielectric Loss Compound (Å)Density Constant Factor × 10⁻³ Formula a c c/a GM/CC BULK FILM BULK FILMColor Sr₂LaSbO₆ 8.325 — 1.0 5.91 16.3 — 3.8 — beige Sr₂PrSbO₆ 8.3908.362 .9966 6.02 10.9 — 2.2 — d. gray* Sr₂NdSbO₆ 8.365 8.320 .9946 6.1310.6 — 2.9 — beige Sr₂SmSbO₆ 8.335 8.295 .9952 6.26 13.6 8.8 <1 9 d.beige Sr₂EuSbO₆ 8.320 8.300 .9975 6.30 14.6 4.6 <1 2 l. yellow*Sr₂GdSbO₆ 8.295 8.280 .9978 6.42 12.1 6.0 <1 9 beige Sr₂TbSbO₆ 8.2808.248 .9961 6.48 12.9 4.6 1.4 4 beige Sr₂HoSbO₆ 8.239 8.218 .9975 6.6411.6 — — 3.1 white Sr₂DySbO₆ 8.248 8.224 .9971 6.64 11.2 — <1 — beigeSr₂ErSbO₆ 8.222 8.204 .9974 6.77 5.3 4.1 1.6 3.2 white Sr₂TmSbO₆ 8.2048.185 .9976 6.86 10.0 — 2.0 — white Sr₂YbSbO₆ 8.190 8.176 .9985 5.87 5.1— <1 — white Sr₂YSbO₆ 8.231 8.216 .9982 6.56 7.1 — 1.4 — white Sr₂LuSbO₆8.188 — 1.0 6.90 15.1 — <1 — beige *“d” denotes dark and “l” denoteslight

Note that all compounds exhibit dielectric constants far superior(lower) than LaAlO₃(22) and some superior to MgO(10). Based on anexperimental error of +/−5%, the following thin film dielectric lossvalues are expected: 14.5-16.1 for Sr₂LaSbO₆; 10.4-11.4 for Sr₂PrSbO₆;10.1-11.1 for Sr₂NdSbO₆; 11.1-12.2 for Sr₂HoSbO₆; 10.6-11.8; forSr₂DySbO₆; 9.5-10.5 for Sr₂TmSbO₆; 4.8-5.4 for Sr₂YbSbO₆; 6.7-7.5 forSr₂YSbO₆; and 14.3-15.9 for Sr₂LuSbO₆. The thin film dielectric lossesin the Sr₂LaSbO₆; Sr₂PrSbO₆; Sr₂NdSbO₆; Sr₂HoSbO₆; Sr₂DySbO₆; Sr₂TmSbO₆;Sr₇YbSbO₆; Sr₂YSbO₆; and Sr₂LuSbO₆ compounds would be expected to beequivalent to the TABLE I empirical bulk values reported above.

All compounds exhibit properties making their use advantageous asdielectric substrates, buffer layers, in antenna structures and a numberof superconductor structures. Pulsed laser ablation targets of thecompounds containing rare earths are prepared as follows:

Stoichiometric amounts of SrCO₃, the rare earth oxides and Sb₂O₃ areweighed out, mixed together in a mortar, pressed into a disc andcalcined at 1000° C. for 15 hours, then cooled to room temperature. Thedisc is ground in a mill to a particle size=100 μm, repressed into adisc, calcined at 1100° C. for 15 hours and cooled to room temperature.The discs are ground to a powder, pressed into a disc and heated asecond time to 1200-1300° C. for 10-15 hours and cooled to roomtemperature. The disc is reground to a particle size of 100 μm, pressedinto a 1¼ inch disc, isostatically pressed at 60000 PSI, sintered at1400-1600° C. for 20 hours and slow cooled to room temperature. In thisconnection, by bulk is meant dense sintered polycrystalline bodies fromabout 1 to 1.25 inch in diameter and about 0.125 inch to ¼ inch thick.X-ray diffractometer traces are run to confirm that each disc is singlephase and the lattice parameters are calculated from the indexedpattern. These compounds are distorted from cubic. They are indexed onthe basis of a tetragonal unit cell with two exceptions, Sr₂LuSbO₆ andSr₂LaSbO₆ that are cubic. See TABLE I. All these compounds form anordered perovskite structure in which alternate B site ions are occupiedby Sb and a rare earth ion. This gives rise to weak reflections in theX-Ray diffraction powder pattern that requires doubling of the unitcell.

It is important to note the significant relationship between the highertemperatures of 1400° C. and 1600° C. for 20-50 hours and the densitiesattained with these materials, The papers “Dielectric constants ofyttrium and rare-earth garnets, the polarizability of gallium oxide andthe oxide-additivity rule,” by R. D. Shannon et al. and “Dielectricpolarizabilities of ions in oxides and fluorides,” by R. D. Shannonestablished that the dielectric constant of a well-behaved complex oxidecan be predicted by knowing the polarizability of the atoms making upthe structure and the volume of the structure. From these relationshipsit is straightforward to understand that the dielectric constant of amaterial is sensitive to the sample's density. For instance, the moreporous the sample (i.e. less dense), the lower the dielectric constantwill be (air has a dielectric constant of roughly 1.00 for a sampledensity approaching 0%). When comparing two samples of the same compoundwith equivalent densities, e.g. both 100% dense, the same dielectricconstant would be expected. However, when comparing two material sampleswith different densities and the same lattice parameter, the dielectricconstant measurements can be appreciably different, again dependent onthe difference in sample density.

Further, the polarizability of Sb⁵⁺, which is a constituent atom of thematerials used to fabricate the compounds and devices of the presentinvention, has not been previously known. The materials of the presentinvention all include at least one Sb⁵⁺ constituent atom with apolarizability of about 1.2 Å³. Therefore, prior art references that donot account for significant factors such as polarizability and materialdensity have not predicted the advantageous dielectric constants of thematerials of the present invention.

Additionally, it should be noted that only two of the compounds in theseries Sr₂RESbO₆ were cubic: Sr₂LuSbO₆ and Sr₂LaSbO₆, both being orderedwith a 1:1 distribution of RE and Sb on B sites, with a perovskiteideally being ABO₃. The ordering leads to a doubling of the unit cell.We have discovered that in order to achieve an ordered cubic singlephase material, sintering at 1600° C. for at least 20 hours in the caseof Sr₂LuSbO₆ and 1400° C. for Sr₂LaSbO₆ for at least 20 hours wereessential. It is also noted that the cubic ordered perovskites preparedin connection with the present invention are quite different from thosefound in the literature because the compounds disclosed herein wereprepared at higher temperatures for a longer period of time. The othercompounds disclosed herein are similarly ordered but are pseudo-cubic,or tetragonal perovskites, which, except for Sr₂NdSbO₆, requiredsintering at temperatures between 1450° C. and 1600° C. for a minimum of10 hours to achieve the tetragonal phase.

LaAO₃ and MgO are often used as substrates on which high criticaltemperature superconducting film such as YBa₂Cu₃O_(7-δ) (YBCO) films aregrown for device applications. The lattice mismatch for heteroepitaxialgrowth of YBCO on LaAlO₃ is outstanding, about 1%. For MgO it is about7%. The mismatch in lattice parameter for the Sr₂RESbO₆ compoundsepitaxially grown on YBCO is given in TABLE II, below. While theirmismatch does not compare favorably with LaAlO₃, several compoundscompare favorably with MgO. In general, the combination of latticematch, low dielectric constant, low dielectric loss, and absence oflattice strain and twinning due to phase transformation make thesecompounds superior to either LaAlO₃ or MgO.

TABLE II % MISFIT TO YBCO a-LATTICE % MISFIT TO COMPOUND PARAMETER aYBCO b YBCO Sr₂LaSbO₆ 8.325 8.2 6.5 Sr₂PrSbO₆ 8.390 8.9 7.2 Sr₂NdSbO₆8.370 8.7 7.0 Sr₂SmSbO₆ 8.330 8.3 6.6 Sr₂EuSbO₆ 8.320 8.2 6.5 Sr₂GdSbO₆8.295 7.7 6.2 Sr₂TbSbO₆ 8.280 7.7 6.0 Sr₂DySbO₆ 8.248 7.3 5.7 Sr₂HoSbO₆8.329 7.2 5.6 Sr₂ErSbO₆ 8.222 7.1 5.3 Sr₂TmSbO₆ 8.204 6.9 5.2 Sr₂YbSbO₆8.190 6.7 5.0 Sr₂YSbO₆ 8.231 7.1 5.4 Sr₂LuSbO₆ 8.188 6.6 4.9

Experimental conditions used to obtain single and multilayeredstructures by laser ablation are described below: Thin films ofSr₂RESbO₆ (where RE=Y, La, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yband Lu) are deposited using the pulsed laser deposition technique. TheKrF laser (λ=248 nm) parameters are a pulse repetition rate of 10 Hz anda laser fluence of 1-2 J/cm² at the target (unless noted otherwise inTABLE III). Chamber deposition conditions TABLE III.

TABLE III Oxygen Block Substrate Pressure Temp Ar # Material MgOYBCO/MgO (mTorr) (° C.) 564 Sr₂YSbO₆ X 170 800 Sr₂LabO₆ Sr₂PrSbO₆Sr₂NdSbO₆ 593a Sr₂SmSbO₆ X 170 750 615 Sr₂EuSbO₆ X 750 593d Sr₂GdSbO₆ X170 800 614 Sr₂TbSbO₆ X 250 750 593c X 170 800 613 Sr₂DySbO₆ X 170 750790 Sr₂HoSbO₆ X X 130 825 593c Sr₂ErSbO₆ X 170 800 684* Sr₂TmSbO₆ X 250785 618 X 100 750 792 Sr₂YbSbO₆ X X 130 825 685* X 250 785 565 X 170 800789 Sr₂LuSbO₆ X X 130 825 *20 Hz laser repetition rate.

X-Ray diffraction analysis of the single layer films, Sr₂RESbO₆/MgOreveals that (400) is the stronger reflection with (200) weaker.However, (220) is strong and (440) weak but both are subsidiary to (400)and (200). For Sr₂RESbO₆/YBCO/MgO (400) and (200) are the primaryreflections. (200) and (440) are present but now they are much weaker.Specific results are given in TABLE IV, below.

TABLE IV OBSERVED SAM- X-RAY REFLECTIONS PLE STRUCTURE YBCO MgOANTIMONATE NO. Sr₂YbSbO₆/MgO 003 002 200 strong AR # 005 220 strong 612006 400 very very weak 007 404 very weak 008 009 Sr₂TmSbO₆/YBCO/MgO 003200 weak AR # 005 002 220 very weak 618 006 400 400 very weak 007 009Sr₂EuSbO₆/YBCO/MgO 003 200 moderate AR # 005 400 very very strong 615006 007 008 Sr₂SmSbO₆/YBCO/MgO 003 200 200 very strong AR # 005 220moderate 593A 006 400 very very strong 007 008 Sr₂YSbO₆/Mgo 200 200strong 400 220 strong 400 very strong 440 weak 600/442 weakSr₂LuSbO₆/YBCO/MgO 003 200 200 Strong AR # 005 400 220 weak 789 006 400very very strong 007 440 very weak 009 442 moderate 0, 0, 10 800 verystrong 0, 0, 11 Sr₂YSbO₆MgO 200 200 weak AR # 220 220 strong 792 400strong 440 weak 444 weak Sr₂HoSbO₆/MgO 200 200 moderate AR # 400 220strong 790 400 very strong 440 moderate Sr₂HoSbO₆/YBCO/MgO 003 200 200strong AR # 005 400 220 moderate 790 006 400 very strong 007 440 weak008 009 0, 0, 10 Sr₂TmSbO₆YBCO/MgO 003 200 200 moderate AR # 005 400 220weak 684 006 400 strong 007 440 weak 008 Sr₂ErSbO₆/YBCO/MgO 003 200 200strong AR # 005 400 220 weak 593C 006 400 very strong 007 008Sr₂ErSbO₆/YBCO/MgO 003 200 200 moderate AR # 005 400 220 weak 615 006400 very strong 007 008 009 0, 0, 10 Sr₂TbSbO₆YBCO/MgO 003 200 200moderate AR # 005 400 220 weak 614 006 400 strong 007 800 weak 009 0, 0,10 0, 0, 11 Sr₂SmSbO₆YBCO/MgO 003 200 200 strong AR # 005 400 220moderate 593A 006 400 very strong 007

The quality of Sr₂RESbO₆ thin films on MgO and YBCO/MgO are very highjudging from the surface reflectivity and the very large intensity ofthe (400) reflections. The latter implies an excellent approach toepitaxial growth especially with respect to YBCO.

Microwave measurements of real and imaginary parts of the dielectricconstant of bulk Sr₂RESbO₆ are performed at approximately 9.32 and 10.1GHz and room temperature. A cavity perturbation technique is used with areflection-type, rectangular cavity excited in either the TE 106 mode(for 9.3 GHZ) or the TE107 mode (for 10.1 GHZ). The cavity is coupled tothe wavelength by an adjustable iris having a 0.5 mm side by 35 mm longslot (cut along the center of one of the broad sides) providing accessfor the thin, rectangular samples cut from bulk Sr₂RESbO₆polycrystalline discs. The samples are held such that their longdimension is parallel to the E-field of the cavity and they arepositioned at the E-field maximum as determined by maximizing the shiftof the cavity.

The real part of the dielectric constant is calculated from the shift inresonance frequency of the cavity due to the sample, and the imaginarycomponent is calculated from a change in in cavity Q. The accuracy ofthese measurements depends upon two general sources of error: 1) theaccuracy of the cavity characterization; and 2) the material propertiessuch as density and and uniformity of shape. Terror due to the cavitycharacterization results in an accuracy of approximately ±2% for thereal part of the characterization results in an of approximately ±2% forthe real part of the dielectric constant, and limits the resolution ofthe loss tangent (the imaginary component divided by the component ofthe real component of the dielectric constant) to approximately 0.001.The error due to material properties and sample shape can beconsiderably greater than the cavity characterization error,particularly the error, particularly the error due to low materialdensity; hence the densities of bulk materials are reported in theDensity GM/CC column of TABLE I.

For thin films, the dielectric constant and loss are obtained by animpedance measurement at 1 MHz. These films are prepared by depositingthe appropriate Sr₂RESbO₆ compound as a film by pulsed laser ablation ona (001) oriented YBCO on (100) oriented MgO substrate, see TABLE III,above. Films with dielectric constants lower than those obtained frombulk measurements may be due to low density in the film, higheroctahedral site ordering and/or measurement used (i.e. the largedifference may arise from the large difference in frequencies 1 MHzversus 10⁶ Hz).

The compounds of the system Sr₂RESbO₆ are psuedo-cubic with departurefrom cubicity of 0.1% or less with Sr₂LuSbO₆ and Sr₂LaSbO₆ that arecubic. The dielectric constants are much lower than LaAlO₆ (22-25) andgenerally range from 5-16, however, even lower dielectric constants of4.1-4.6 are reported for several thin films listed in TABLE I, and themuch lower to dielectric constant achieved herein is an important factorcontributing toward the usefulness of the compounds disclosed herein innumerous structures and devices such as dielectric substrates, bufferlayers, antennas, thin films and so on.

In the foregoing disclosure, by the term “high critical temperature thinfilm superconductor device” is meant a copper oxide superconductorhaving a critical temperature in excess of 30 K. Examples of suchsuperconductors are: REBa₂Cu₃O_(7-δ), REBa₂Cu₄O₈ where RE is a rareearth element and 0≦δ≦1, Tl₂Ca₂Ba₂Cu₃O₁₀, Tl₁Ca₂Ba₂Cu₃O₉andTl₂Ba₂Ca₁Cu₂O₈ as well as Hg-based superconductors.

A single layer device refers to a device including a single layer ofhigh critical temperature superconducting ferroelectric, pyroeletric,piezoelectric, or ferromagnetic material. A multi-layer device refers toa device including at least two layers of a high critical temperaturesuperconductor, ferroelectric, pyroeletric, piezoelectric, dielectric orferromagnetic materials.

High critical temperature superconducting, dielectric, ferroelectric,pyroelectric, piezoelectric, and ferromagnetic materials and thecompounds of this invention can be used in numerous devices includingflux flow transistors, current limiters, broadband impedancetransformers, diodes, delay lines, resonators, antenna, antenna feeds,switches, phase shifters, mixers, amplifiers, balomoters andmagneto-resistors.

The compounds of the invention can be made in the form of a bulk singlecrystal substrate, a dense polycrystalline disc, a crystallineexpitaxial thin film or a polycrystalline thin film. In theirmanufacture, some form of laser ablation is preferred, but the compoundscan also be made by sputtering, MOCVD, MBE, evaporation, etc.

In addition to numerous device already disclosed throughout thisspecification, the following examples illustrate two specific devicescomposed of Sr₂RESbO₆ compounds in accordance with this invention.

An antenna can be made according to the invention by depositing a singlelayer of high critical temperature superconductor (HTSC) directly onto asingle crystal Sr₂LuSbO₆ substrate or a substrate of other compositionbuffered with a layer of Sr₂LuSbO₆. The HTSC is then patterned tocomplete the device.

A superconductor insulator superconductor step edge Josephson junction,a multilayer superconducting device, is fabricated according to theinvention using Sr₂YbSbO₆. More particularly, the device is made bydepositing a single layer of HTSC on a single crystal Sr₂YbSbO₆substrate or a substrate of other composition buffered with a layer ofSr₂YbSbO₆. Next, the HTSC is patterned by ion milling at a 45° angle. Alayer of Sr₂YbSbO₆ is then deposited. Next, another HTSC layer isdeposited and patterned to complete the device.

We wish it to be understood that we do not desire to be limited to theexact details of construction shown and described for obviousmodifications will occur to a person skilled in the art.

What we claim is:
 1. A dielectric substrate of the general formulaSr₂RESbO₆, further comprising: said RE being Ytterbium; said dielectricsubstrate being constructed of Sr₂YbSbO₆; said general formula includingan Sb⁵⁺ constituent atom with a polarizability of about 1.2 Å³; saiddielectric substrate being heated for at least 20 hours at between 1400°C. and 1600° C.; said dielectric substrate is constructed in a bulkform; said dielectric substrate having an ordered perovskitepseudo-cubic tetragonal crystalline structure; said dielectric substratehaving a low dielectric constant of 5.1; and said dielectric substratehaving a low dielectric loss of less than 1.0×10⁻³ without a phasetransition.
 2. A dielectric substrate of the general formula Sr₂RESbO₆,further comprising: said RE being Thulium; said dielectric substratebeing constructed of Sr₂TmSbO₆; said general formula including an Sb⁵⁺constituent atom with a polarizability of about 1.2 Å³; said dielectricsubstrate being heated for at least 20 hours at between 1400° C. and1600° C.; said dielectric substrate is constructed in a bulk form; saiddielectric substrate having an ordered perovskite pseudo-cubictetragonal crystalline structure; said dielectric substrate having a lowdielectric constant of 10.0; and said dielectric substrate having a lowdielectric loss of 2.0×10⁻³ without a phase transition.
 3. A dielectricsubstrate of the general formula Sr₂RESbO₆, further comprising: said REbeing Erbium; said dielectric substrate being constructed of Sr₂ErSbO₆;said general formula including an Sb⁵⁺ constituent atom with apolarizability of about 1.2 Å³; said dielectric substrate being heatedfor at least 20 hours at between 1400° C. and 1600° C.; said dielectricsubstrate is constructed in a bulk form; said dielectric substratehaving an ordered perovskite pseudo-cubic tetragonal crystallinestructure; said dielectric substrate having a low dielectric constant of5.3; and said dielectric substrate having a low dielectric loss of lessthan 1.6×10⁻³ without a phase transition.
 4. A dielectric substrate ofthe general formula Sr₂RESbO₆, further comprising: said RE beingHolmium; said dielectric substrate being constructed of Sr₂HoSbO₆; saidgeneral formula including an Sb⁵⁺ constituent atom with a polarizabilityof about 1.2 Å³; said dielectric substrate being heated for at least 20hours at between 1400° C. and 1600° C.; said dielectric substrate isconstructed in a bulk form; said dielectric substrate having an orderedperovskite pseudo-cubic tetragonal crystalline structure; saiddielectric substrate having a low dielectric constant of 11.6; and saiddielectric substrate having a low dielectric loss of about 3.1×10⁻³without a phase transition.
 5. A dielectric substrate of the generalformula Sr₂RESbO₆, further comprising: said RE being Dysprosium; saiddielectric substrate being constructed of Sr₂DySbO₆; said generalformula including an Sb⁵⁺ constituent atom with a polarizability ofabout 1.2 Å³; said dielectric substrate being heated for at least 20hours at between 1400° C. and 1600° C.; said dielectric substrate isconstructed in a bulk form; said dielectric substrate having an orderedperovskite pseudo-cubic tetragonal crystalline structure; saiddielectric substrate having a low dielectric constant of 11.2; and saiddielectric substrate having a low dielectric loss of 1.0×10⁻³ without aphase transition.
 6. A dielectric substrate of the general formulaSr₂RESbO₆, further comprising: said RE being Terbium; said dielectricsubstrate being constructed of Sr₂TbSbO₆; said general formula includingan Sb⁵⁺ constituent atom with a polarizability of about 1.2 Å³; saiddielectric substrate being heated for at least 20 hours at between 1400°C. and 1600° C.; said dielectric substrate is constructed in a bulkform; said dielectric substrate having an ordered perovskitepseudo-cubic tetragonal crystalline structure; said dielectric substratehaving a low dielectric constant of 12.9; and said dielectric substratehaving a low dielectric loss of 1.4×10⁻³ without a phase transition. 7.A dielectric substrate of the general formula Sr₂RESbO₆, furthercomprising: said RE being Yttrbium; said dielectric substrate beingconstructed of Sr₂YSbO₆; said general formula including an Sb⁵⁺constituent atom with a polarizability of about 1.2 Å³; said dielectricsubstrate being heated for at least 20 hours at between 1400° C. and1600° C.; said dielectric substrate is constructed in a bulk form; saiddielectric substrate having an ordered perovskite pseudo-cubictetragonal crystalline structure; said dielectric substrate having a lowdielectric constant of 7.1; and said dielectric substrate having a lowdielectric loss of 1.4×10⁻³ without a phase transition.
 8. A dielectricsubstrate of the general formula Sr₂RESbO₆, further comprising: said REbeing Lanthanium; said dielectric substrate being constructed ofSr₂LaSbO₆; said general formula including an Sb⁵⁺ constituent atom witha polarizability of about 1.2 Å³; said dielectric substrate being heatedfor at least 20 hours at between 1400° C. and 1600° C.; said dielectricsubstrate is constructed in a bulk form; said dielectric substratehaving an ordered perovskite cubic crystalline structure; saiddielectric substrate having a low dielectric constant of 16.3; and saiddielectric substrate having a low dielectric loss of 3.8×10⁻³ without aphase transition.
 9. A dielectric substrate of the general formulaSr₂RESbO₆, further comprising: said RE being Gadolinium; said dielectricsubstrate being constructed of Sr₂GdSbO₆; said general formula includingan Sb⁵⁺ constituent atom with a polarizability of about 1.2 Å³; saiddielectric substrate being heated for at least 20 hours at between 1400°C. and 1600° C.; said dielectric substrate is constructed in a bulkform; said dielectric substrate having an ordered perovskitepseudo-cubic tetragonal crystalline structure; said dielectric substratehaving a low dielectric constant of 12.1; and said dielectric substratehaving a low dielectric loss of 1.0×10⁻³ without a phase transition. 10.A dielectric substrate of the general formula Sr₂RESbO₆, furthercomprising: said RE being Samarium; said dielectric substrate beingconstructed of Sr₂SmSbO₆; said general formula including an Sb⁵⁺constituent atom with a polarizability of about 1.2 Å³; said dielectricsubstrate being heated for at least 20 hours at between 1400° C. and1600° C.; said dielectric substrate is constructed in a bulk form; saiddielectric substrate having an ordered perovskite pseudo-cubictetragonal crystalline structure; said dielectric substrate having a lowdielectric constant of 13.6; and said dielectric substrate having a lowdielectric loss of less than 1.0×10⁻³ without a phase transition.
 11. Adielectric substrate of the general formula Sr₂RESbO₆, furthercomprising: said RE being Praseodymium; said dielectric substrate beingconstructed of Sr₂PrSbO₆; said general formula including an Sb⁵⁺constituent atom with a polarizability of about 1.2 Å³; said dielectricsubstrate being heated for at least 20 hours at between 1400° C. and1600° C.; said dielectric substrate is constructed in a bulk form; saiddielectric substrate having an ordered perovskite pseudo-cubictetragonal crystalline structure; said dielectric substrate having a lowdielectric constant of 10.9; and said dielectric substrate having a lowdielectric loss of 2.2×10⁻³ without a phase transition.
 12. A dielectricsubstrate of the general formula Sr₂RESbO₆, further comprising: said REbeing Europium; said dielectric substrate being constructed ofSr₂EuSbO₆; said general formula including an Sb⁵⁺ constituent atom witha polarizability of about 1.2 Å³; said dielectric substrate being heatedfor at least 20 hours at between 1400° C. and 1600° C.; said dielectricsubstrate is constructed in a bulk form; said dielectric substratehaving an ordered perovskite pseudo-cubic tetragonal crystallinestructure; said dielectric substrate having a low dielectric constant of14.6; and said dielectric substrate having a low dielectric loss of lessthan 1.0×10⁻³ without a phase transition.
 13. A dielectric substrate ofthe general formula Sr₂RESbO₆, further comprising: said RE beingNeodymium; said dielectric substrate being constructed of Sr₂NdSbO₆;said general formula including an Sb⁵⁺ constituent atom with apolarizability of about 1.2 Å³; said dielectric substrate being heatedfor at least 20 hours at between 1400° C. and 1600° C.; said dielectricsubstrate is constructed in a bulk form; said dielectric substratehaving an ordered perovskite pseudo-cubic tetragonal crystallinestructure; said dielectric substrate having a low dielectric constant of10.6; and said dielectric substrate having a low dielectric loss of2.9×10⁻³ without a phase transition.